Roasting system having self-aligning agitator and door bearing assembly

ABSTRACT

A bean roasting system includes a roasting drum, an agitator, and a door. The roasting drum has an inside surface extending from a back end to a front end. The agitator has blades mounted to an axial shaft. The axial shaft has an anterior end portion. The door is mounted rotationally relative to the roasting drum and includes a glass plate and a bearing assembly. The glass plate provides visual access to contents inside the roasting drum when the door is closed. The bearing assembly includes an outer housing and an inner bearing. The outer housing is mounted to the glass plate. The inner bearing defines a receiving hole that receives and supports the anterior end portion of the axial shaft when the door closed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/386,727, entitled “Roasting System Having Self-Aligning Agitator andDoor Bearing Assembly,” filed Apr. 17, 2019, which claims priority toU.S. Provisional Application Number 62/660,588, entitled “RoastingSystem Having Self-Aligning Agitator and Door Bearing Assembly,” filedon Apr. 20, 2018, each of which is incorporated herein by reference.

FIELD OF THE DISCLOSURE

The present disclosure pertains to the roasting of food products,particularly to beans, and more particularly to coffee beans. Yet moreparticularly the present disclosure describes a roasting system that hasan improved roasting drum that allows contents to be visually observedduring a roasting process while providing a self-aligning mechanicalmount for an internal bean agitator.

BACKGROUND

Food roasting machines are in wide use. One particularly common roastingmachine is utilized to prepare coffee beans to be either packaged orground and brewed. A typical roasting machine includes a roastingchamber for supporting, agitating, and roasting beans. It is desirableto be able to visually observe beans as they are roasting. It isdesirable to provide this function while also providing a stablemechanical system for automated agitation of the beans.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram schematic of an example roasting system.

FIG. 2 is an electrical block diagram of an example roasting system.

FIG. 3 is a flowchart representing an example sequence of operation fora roasting system.

FIG. 4 is a graphical representation of an example of a roasting profileincluding graphs of temperature (solid) and humidity (dashed) versustime.

FIG. 5 is a flowchart representing a process that can take place duringa roasting operation.

FIG. 6 is a flowchart depicting an example method by which a controllermodulates temperatures for catalytic converter and roasting chamber fora given operating mode, according to an embodiment.

FIG. 7 is an isometric view of a portion of a roasting chamber assembly,according to an embodiment.

FIG. 8 is a top view of a roasting chamber assembly that is partiallyshown in FIG. 7.

FIG. 9 is an isometric drawing of the door of FIG. 7, in isolation.

FIG. 10 is a sectional view taken from AA′ of FIG. 9 to illustrateassembled components of a door.

FIG. 11 is a detailed view taken from FIG. 10 to illustrate a centralpart of a door.

FIG. 12 is an isometric view of the agitator of FIG. 7, in isolation.

FIG. 13 is similar to FIG. 11 except that FIG. 13 includes an anteriorend of a shaft received into a central hole of an inner bearing.

FIG. 14 is a method of self-aligning an axis of an agitator to an axisof a roasting drum in response to a door closure, according to anembodiment.

FIG. 15A is an isometric view of a roasting chamber assembly of FIG. 7without an outer door and with an opening in a bottom surface of a drumin a sealed state.

FIG. 15B is similar to FIG. 15A except that the opening in the bottomsurface of the drum is in an open state.

FIG. 16A is an isometric view of a lower outer portion of the drum ofFIG. 7 in a sealed state.

FIG. 16B is an isometric view of a lower outer portion of the drum ofFIG. 7 in an open state.

FIG. 17 is a flowchart of a method for removing contents of a roastingdrum, according to an embodiment.

SUMMARY

In an aspect of the disclosure, a bean roasting system includes aroasting drum, an agitator, and a door. The roasting drum has an insidesurface extending from a back end to a front end. The agitator hasblades mounted to an axial shaft. The axial shaft has an anterior end.The door is mounted rotationally relative to the roasting drum andincludes a glass plate and a bearing assembly. The glass plate providesvisual access to contents inside the drum when the door is closed. Thebearing assembly includes an outer housing and an inner bearing. Theouter housing is mounted to the glass plate. The inner bearing defines areceiving hole that receives and supports the anterior end of the axialshaft when the door closed.

In one implementation the axial shaft has a posterior end. The beanroasting system includes an agitator motor coupled to the posterior endof the axial shaft.

In another implementation the agitator blades rest against a lowerinside surface of the roasting drum when the door is rotated away fromthe roasting drum and in an open position. Moving the door to the closedposition causes the receiving hole of the bearing assembly to engage theanterior end portion and lift to the blade assembly off of the lowerinside surface of the drum.

In yet another implementation the receiving hole in the bearing assemblyis tapered to provide an alignment between the receiving hole and theanterior end portion of the axial shaft. The axial shaft tapers towardthe anterior end portion. The axial shaft anterior end portion has ataper angle that substantially matches a taper angle of the receivinghole.

In a further implementation the bearing assembly includes a circularball bearing race between the outer housing and the inner bearing of thebearing assembly.

In a yet further implementation the glass plate has a central opening.The bearing assembly seals to the glass plate to seal the centralopening in the glass plate.

In another implementation the inside surface of the drum defines acentral axis of the drum. The axial shaft of the agitator defines acentral axis of the agitator. The central axis of the drum is aligned tothe central axis of the agitator when the anterior end portion of theaxial shaft engages the receiving hole as the door is moved to a closedposition.

DETAILED DESCRIPTION

The following description incorporates content from patent applicationU.S. patent application Ser. No. 15/949,903, filed on Apr. 10, 2018which is a non-provisional counterpart of U.S. Provisional ApplicationSer. No. 62/485,206, Entitled “ROASTING SYSTEM WITH CLEAN EMISSIONS ANDHIGH THERMAL EFFICIENCY” by Ricardo Lopez et al., filed on Apr. 13, 2017which is hereby incorporated by reference.

FIG. 1 is a block diagram schematic of roasting system 2, according toan embodiment. Roasting system 2 includes a roasting chamber 4 having agas outlet 6 and a gas inlet 8. A gas conduit 10, in combination withother relevant components discussed below, defines a recirculating gasflow path (referenced herein interchangeably as gas conduit 10 orrecirculating gas flow path 10) and is coupled to and includes theroasting chamber 4. The recirculating gas flow path 10 performs a numberof functions including removing debris and noxious gases from theroasting process and regulating a temperature of the roasting chamber 4.The roasting system 2 also includes a bean hopper 12 for a loadingunroasted beans before they are inputted to the roasting chamber 4.Between the bean hopper 12 and the roasting chamber 4 is a load valve 14for releasing the beans from the hopper 12 into the roasting chamber 4.An unload valve 16 is for releasing the beans to a bean cooling system(not shown).

During operation of the roasting system 2 a flow stream 18 of gas isestablished in the recirculating gas flow path 10 from the gas outlet 6to the gas inlet 8 of the roasting chamber 4. After leaving the gasoutlet 6 the flow stream 18 passes to a cyclonic separator 20, whichremoves debris from the gas flow stream 18 that is collected below thecyclonic separator 20.

The flow stream 18 then passes to a variable diverter 22. Variablediverter 22 splits the gas flow path 10 into at least two flow pathsegments including a treated flow path segment 24 and a bypass flowsegment 26. The variable diverter 22 controls a “bypass percentage,”which is a percentage of the flow stream 18 that is diverted into thebypass flow segment 26.

The bypass percentage can be varied between zero percent to 100 percentof the mass flow of the flow stream 18. When the bypass percentage iszero then all of the mass flow of the flow stream 18 is flowing throughthe treated flow path segment 24. When the bypass percentage is X, then100−X percent of the mass flow of the flow stream is passing through thetreated flow segment 24 and X percent of the mass flow of the flowstream 18 is passing through the bypass flow segment 26. When the bypasspercentage is 100, then all of the mass flow of the flow stream 18 ispassing through the bypass flow segment 26.

The treated flow segment 24 includes a heater 28 and a catalyticconverter 30 in a fluidic series. In the embodiment shown in FIG. 1, theheater 28 is the main heater 28 for the catalytic converter 30 and theroasting chamber 4. The catalytic converter 30 has an operatingtemperature (referred to as a catalyst temperature T_(CT)) that is usedfor catalysis. A catalyst temperature T_(CT) is typically in a range of500 to 1000 degrees Fahrenheit. On the other hand, the roasting chamber4 has a roasting chamber temperature T_(RC) that can vary between 150and 500 degrees Fahrenheit depending upon a desired roasting process anda step within the process.

The bypass flow segment 26 is coupled to a mixing chamber 32 (alsoreferred to herein as a junction 32). The mixing chamber 32 (junction32) defines the point at which the separated or split flow pathsrecombine into one flow path. Between the junction 32 and the gas inlet8 of the roasting chamber 4 is a main blower 34.

Coupled to the bypass flow segment 26 is an inlet component 36 to allowambient air to enter the recirculating gas flow path 10. The inletcomponent 36 includes an inlet control valve and inlet blower coupled inseries to allow and force ambient air into the recirculating gas flowpath 10. Coupled to the mixing chamber 32 is an outlet component 38 torelease gas from the recirculating gas flow path 10 to the ambientenvironment. The outlet component 38 includes an outlet control valve, acondenser, and a filter in series.

The roasting system 2 employs various sensors 40 including temperaturesensors T. These sensors 40 are utilized to enable a closed loop controlof various processes within the roasting system 2.

In alternative embodiments the bypass flow segment can include anauxiliary heating and/or cooling temperature modulator 44. In anotheralternative embodiment the main blower 34 can be located at otherlocations in the recirculating gas flow path 10 or multiple blowers canbe employed. In yet another alternative embodiment, the inlet component36 may be integrated into the mixing chamber, and the outlet component38 may be moved to a point in the fluid flow path that is immediatelyafter the catalytic converter.

FIG. 2 is an electrical block diagram of the roasting system 2 ofFIG. 1. Some reference numbers in FIG. 2 correspond to reference numbersin FIG. 1. Roasting system 2 includes a controller 42 that receivessignals from sensors 40 and provides control signals to variouscomponents including valves 14 and 16, variable diverter 22, main heater28, main blower 34, inlet component 36, outlet component 38, andoptionally an auxiliary temperature modulator 44 (providing heatingand/or cooling). The controller is also controllably coupled to anagitator motor 41 and a bean drop actuator 43.

Controller 40 includes a processor 46 coupled to an information storagedevice 48. The information storage device 48 includes a non-transient ornon-volatile storage device storing software that, when executed byprocessor 46, controls the various components of roasting system 2 andprovides functions for which the controller 42 is configured. Thecontroller 42 can be a located at one location or distributed amongmultiple locations in roasting system 2. For example, controller 42 canbe disposed within a housing (not shown) of roasting system 2 and/or ahousing of an appropriate component of roasting system 22 such as ahousing of the variable diverter 22. The controller can be electricallyand/or wirelessly linked to the various components of roasting system 2.

The controller 42 is configured to define and activate a plurality ofdifferent predetermined or predefined operating modes. Each operatingmode can define a step or process in a sequence of steps and processesthat are executed during the operation of the roasting system 2. Anexample sequence will be described with respect to FIG. 3.

A particular operating mode can be defined, for example, in part by atime duration and a state of various components of the roasting system2. States that are directly controlled are those of components thatreceive direct control signals from the controller 42. Examples ofdirectly controlled states include the bypass percentage of the variablediverter 22, an output power of the main heater 28, an airflow rate ofthe main blower 34, and a control of the inlet and outlet components 36and 38 respectively. An optional example would be control of auxiliarytemperature modulator 44.

States that are indirectly determined are those states that are aconsequence of those states that are directly determined. These includea temperature of the roasting chamber 4 and an internal temperature ofthe catalytic converter 30. These temperatures are determined (andthereby indirectly controlled) through the control of the main heater28, the main blower 34, and the variable diverter 22.

Controller 42 reads signals or data from sensors 40 indicative ofvarious temperatures within the roasting system 2. These signals or datamay be indicative of a temperature of the roasting chamber 4, thecatalytic converter 30, or various portions of the recirculating flowpath 10. The controller 42 then modulates the directly controlled statesto maintain desired temperature set points.

The controller also configured to operate the agitator motor 41 and thebean drop actuator 43 when beans are dropped from the roasting chamber 4to a cooling chamber. This will be described in detail infra.

FIG. 3 is a flowchart representing an example sequence of operation 50for the roasting system 2. Each step of the operational sequence isbased upon a predetermined operating mode an indicator for which isstored in controller 42. For each of these steps the controller 42controls various components as discussed with respect to FIG. 2.

Step 52 represents an initial state of the roasting system 2 after ithas been off long enough to equilibrate with an ambient environment. Theheater power is zero, meaning that no power is being sent to main heater28. The main blower 34 is off. As a result the catalytic converter 30temperature and the roasting chamber 4 temperatures are both at ambienttemperature which can be about 70 degrees Fahrenheit.

Step 54 represents a pre-heat mode for the roasting system 2. Thisoperational mode can have a time duration of about 30 minutes. Duringthis mode the power delivered to the main heater 28 is in a “high”state. In one implementation the power delivered to main heater 28 ismore than 75 percent or even 100 percent of the maximum power level thatis used for the main heater 28. The main blower 34 is operated in a“high” state. In one particular implementation the main blower 34 isoperated with a flow rate of 200 cubic feet per minute, and the bypasspercentage starts out at a low value or less than 10 percent or evenzero and then ramps up to bypass percentage of more than 50 percent,more than 75 percent or about 85 to 90 percent. In anotherimplementation, the bypass percentage is kept at a low value throughoutpreheat, and the blower speed is decreased as the system heats up inorder to reduce the delivery energy to various parts of the system. Inthis case, the heater temperature remains high, but the energy drawn andoutputted by the heater is lower due to the decrease in energytransport. During the pre-heat mode the temperature of the catalyticconverter 30 ramps up from ambient temperature to an effective catalytictemperature in a range of 500 to 1000 degrees Fahrenheit. In oneimplementation the catalytic temperature is about 800 degreesFahrenheit. The roast chamber 4 temperature also ramps up to atemperature range to begin the roasting process. In one embodiment thistemperature is in a range of 300 to 400 degrees Fahrenheit or about 350degrees Fahrenheit.

Step 56 represents a standby mode that has an indeterminate duration.During this operational mode the power delivered to the main heater 28is in a “low” state. In one implementation the power delivered to heater28 is less than 50 percent in a range of about 5 to 15 percent of themaximum power level that is used for the main heater. This low mainheater 28 power is all that is used to maintain the catalytic converter30 temperature and the roasting chamber 4 temperature. In oneimplementation, the main blower is operated in a “low” state. In oneimplementation the main blower is operated with a flow rate of 100 cubicfeet per minute (CFM). In this case, the bypass percentage is more than50 percent, more than 75 percent, or in a range of about 85 to 90percent. In another implementation, the main blower operates at anoutput less than 100 cubic feet per minute (CFM), and the speed ismodulated to control the energy distribution throughout the system. Inthis case, the bypass percentage is kept low, around 0-10 percent. Inall cases, catalytic converter 30 temperature is in a range of 500 to1000 degrees Fahrenheit or about 800 degrees Fahrenheit. The roastingchamber 4 temperature is in a range of 300 to 400 degrees Fahrenheit orabout 350 degrees Fahrenheit.

Step 58 represents an operational mode in which the valve 14 is openedto load beans from the hopper 12 to the roasting chamber 4. Thecomponent states for step 58 are the same as those of step 57 exceptthat the main blower is operated in a “high” state. In oneimplementation the main blower 34 is operated with a flow rate of 200cubic feet per minute.

Steps 60, 62, and 64 represent a complete cycle for bean roasting.During these steps the main blower 34 is operated in a “high” statewhich can be 200 cubic feet per minute. The combined time duration forsteps 60, 62, and 64 is about 10-15 minutes.

Step 60 is an operational mode for drying the beans, which can lastabout 1-3 minutes. The main heater 28 is operated with a “low” powerlevel, which can be in a range of 10 to 20 percent of maximum power. Thebypass percentage is in a range of 50 to 90 percent or about 71 percent.The catalyst temperature in a range of 500 to 1000 degrees Fahrenheit orabout 800 degrees Fahrenheit. The roast chamber 4 temperature is in arange of about 170 to 180 degrees Fahrenheit or about 175 degreesFahrenheit.

Step 62 is a “recovery ramp” mode during which the roasting chambertemperature is increased to a roasting development temperature. The“recovery ramp” mode can have a duration of about 3-6 minutes. The mainheater 28 is operated with a “high” power level which can be in a rangeof 75 to 100 percent of maximum power. The bypass percentage is in arange of zero to 10 percent so that some gas having a higher temperaturefrom the main heater 28 is directed to the roasting chamber 4. As aresult, the roasting chamber temperature increases to a roastingdevelopment temperature, which can be about 390 degrees Fahrenheit.During step 62 the catalyst temperature may fall to about 650 degreesFahrenheit.

Step 64 is a roasting development mode during which the temperature ofthe roasting chamber 4 is increased. The roasting development mode has aduration of about 3 minutes. The main heater 28 is operated with a “low”power that can be 20 to 30 percent of maximum power. The bypasspercentage is in a range of 50 to 100 percent or about 76 percent. Thebypass percentage can be increased while the heater input is decreasedduring this mode. The roasting chamber 4 temperature increases fromabout 390 degrees Fahrenheit to about 460 degrees Fahrenheit. Thecatalyst temperature increases from about 650 degrees Fahrenheit toabout 750 degrees Fahrenheit. Also as part of this mode, the inlet 36and outlet 38 components are operated to allow a one to five percent gasexchange with the ambient air environment.

During step 66 the valve 16 is opened to drop the roasted beans into acooling chamber. During step 68 the beans are cooled and the systemstates are returned to those of the standby mode of step 56 after apreheating operation.

As a note, the specific states described above with respect to FIG. 3can vary depending on a desired “roasting profile.” In particular, theroasting chamber 4 temperature states are a function of such a roastingprofile. Thus, the described sequence 50 can have variations in terms ofcomponent states and the temperatures indicated with respect to FIG. 3are examples for a particular roasting profile or set of roastingprofiles.

Referring to FIG. 1, the sensors 40 can include humidity (designated H)and oxygen (designated 02) sensors. The controller 42 can useinformation from these sensors to track progress of the roasting steps60-64 (of FIG. 3). As a unique example, the controller 42 can inferinformation about the roast process by analyzing the humidity versustime of gas that is exiting the outlet 6 of the roasting chamber 4.

A milestone event during roasting steps 60-64 is a “first crack” of thebeans. Once this begins, the remaining time and temperature of theroasting profile can be more accurately determined. The added time andtemperature is dependent on the type of roast (e.g., light roast versusfull French roast).

FIG. 4 is a graph of an example of temperature and humidity versus time.The values in this graph are generated using sensors 40 that are placedat or proximate to the outlet 6 of the roasting chamber 4. As shown, arelatively sharp peak in the graph of humidity versus time correspondsto the “first crack” milestone of the roasting development step 64.

FIG. 5 is a flowchart depicting an example roasting process 70. Roastingprocess 70 can be similar to and/or preformed in conjunction with theroasting steps 60-64 except that it incorporates additional operations.According to step 72, the humidity is monitored by the H sensor 40 atthe outlet 6 of roasting chamber 4. As part of step 72, the controller42 analyzes the graph of humidity versus time (or an equivalent such asa look-up table stored in memory, an equation presenting thehumidity-time curve) to identify rapid changes in a magnitude of theslope and a localized maximum.

According to step 74, a humidity peak is identified. This corresponds tothe “first crack” of the beans. This identification of the humidity peakindicates a certain progress of the roasting process 70.

According to step 76, a response or action is activated in response tothe identification of the first crack milestone. This can take anynumber of forms.

In one implementation the roast development duration is automaticallyadjusted based upon the milestone identification and a desired roasttype. In this implementation parameters such as the heater power,airflow, and/or bypass percentages can also be adjusted.

In another implementation an alert can be automatically sent to a personwho is responsible for the roasting operation. For example, this can bea message wirelessly sent to a mobile device that is utilized by theperson. The message can provide an option for the person to adjust theroast profile based upon the timing of the milestone.

FIG. 6 is a flowchart depicting an example method 80 by which thecontroller 42 modulates temperatures for the catalytic converter 30 andthe roasting chamber 4 for a given operating mode. As discussed above,the catalytic converter 30 temperature T_(CT) can be maintained at anoptimum temperature for catalysis that tends not to change as a functionof an operating mode of the roasting system 2. On the other hand, theroast chamber 4 temperature T_(RC) is a function of the operating mode.

According to step 82 the method 80 begins with a receipt of operatingparameters for an operating mode including a specified roast chambersetting T_(RC). The method 80 then includes two independent temperaturecontrol loops that can be executed concurrently. An example catalyticconverter 30 temperature T_(CT) control loop is depicted by steps 84 to88. An example roasting chamber 4 temperature control loop is depictedby steps 90 to 94.

According to step 84 a temperature T_(CT) of the catalytic converter 30is monitored. As part of step 84, the controller 42 receives temperatureT_(CT) data for the catalytic converter 30 from a temperature sensor 40that is within or proximate to or receiving air exiting from thecatalytic converter 30.

According to step 86 a determination is made as to whether thetemperature T_(CT) of the catalytic converter 30 is within a specifiedrange. This specified temperature range is within an overall temperaturerange of for example 500 to 1000 degrees Fahrenheit. In oneimplementation the specified temperature range is narrower and centeredaround a temperature of about for example 800 degrees Fahrenheit. If thetemperature T_(CT) of the catalytic converter 30 deviates from thespecified range, then the method 80 proceeds to step 88. According tostep 88 a power delivered to the main heater 28 is adjusted tocounteract the temperature deviation determined in step 86. As part ofstep 88 the controller 42 sends a control signal to adjust a power inputto the heater 28. Then steps 84 and 86 are repeated. When according tostep 86 the temperature T_(CT) of the catalytic converter 30 is withinthe specified range, the loop proceeds to step 84 to continue monitoringthe temperature T_(CT) of the catalytic converter 30.

According to step 90 a temperature T_(RC) of the roasting chamber 4 ismonitored. As part of step 90, the controller 42 receives temperatureT_(RC) data for the roasting chamber 4 from a temperature sensor 40 thatis either within or proximate to or receiving air exiting from roastingchamber 4.

According to step 92 a determination is made as to whether thetemperature T_(RC) of the roasting chamber 4 is within a specifiedrange. This specified range is based upon the specified roast chambertemperature setting T_(RC) for the current operating mode from step 82.If the temperature T_(RC) of the roasting chamber 4 deviates from thespecified range, then the method 80 proceeds to step 94.

According to step 94, the variable diverter 22 is adjusted to counteractthe deviation. As part of step 94 the controller 42 sends a controlsignal to the variable diverter 22. In response to the control signal,the variable diverter 22 increases or decreases the bypass percentage.For example, if the temperature is too high then the bypass percentagewill be increased. Then steps 90 and 92 are repeated. When according tostep 92 the temperature T_(RC) of the roasting chamber 4 is within thespecified range, the loop proceeds to step 90 to continue monitoring thetemperature T_(RC) of the roasting chamber 4.

The two temperature control loops for the catalytic converter 30 and theroasting chamber 4 continue independently of each other from theperspective of a control system operation. However, they do have anindirect dependency. When the heater 28 is adjusted according to step 88this will impact the temperature T_(RC) of the roasting chamber 4. Thenthe control loop for the roasting chamber 4 will most likely need torespond.

FIGS. 7-13 and 15-16 illustrate an embodiment of a roasting chamberassembly 4. In describing roasting chamber assembly 4, mutuallyorthogonal axes X, Y, and Z will be used. The axes X and Y are generallylateral axes that can be very nearly horizontal. Axis Z is a verticalaxis that can be very nearly aligned with a gravitational reference. Thedirection +X is toward the front or anterior and the direction −X istoward the back or posterior. The direction +Z is upward and thedirection −Z is downward.

FIG. 7 is an isometric view of a portion of the roasting chamberassembly 4. Roasting chamber assembly 4 includes a cylindrical roastingdrum 100 defining a horizontal central axis that is aligned with theX-axis. The drum 100 extends from a back end 102 to a front end 104. Thefront end 104 of the drum 100 is proximate to a front portion 106 of theroasting chamber assembly 4. In the illustrated embodiment, the frontportion 106 is a front plate 106. In other embodiments, the frontportion or plate 106 can be a portion of a housing of the roastingchamber assembly 4. Front plate 106 defines a vertical opening 108 thatis proximate to the front end 104 of the drum.

Within the drum 100 is an agitator 110 including a plurality of blades112 mounted to a shaft 114. The central shaft 114 has an anterior endportion 116 with a conical taper. The anterior end portion 116 tapers inthe +X direction. The shaft 114 has a posterior end 118 (FIG. 8 which isa top view of the roasting chamber assembly 4) that is proximate to theback end 102 of drum 100. The posterior end 118 of shaft 114 is coupledto the agitator motor 41. The agitator motor 41 is configured to rotatethe agitator 110 about the shaft 114.

A lower surface 101 of the drum 100 is partly defined by a hatch 120.The hatch 120 can be lowered to provide an opening in the bottom of thedrum 100. This allows beans contained in the drum 100 to be emptied intoa cooling chamber. Details of the hatch will be discussed infra.

A door 122 is mounted to the front plate 106 by a hinge 124. The door122 can be rotated inwardly about the hinge 124 so that a pin 126 can belatched by a catch 128. In the latched state, the door 122 closes andseals the vertical opening 108 in front plate 106. The door includes aglass plate 130 that allows the contents of the drum 100 to be viewedduring a roasting operation. The door 122 also includes a bearingassembly 132 configured to receive the anterior end portion 116 of theshaft 114 when the door 122 is closed upon the opening 108. Thus, thebearing assembly 132 supports the agitator 110.

FIG. 8 is a top view of the roasting chamber assembly 4. Illustrated isthe horizontal central axis 133 of the drum 100. Horizontal central axis133 is aligned with an axis of rotation of the agitator motor 41 andagitator 110.

FIG. 9 is an isometric drawing of the door 122 in isolation. The bearingassembly 132 is centrally supported upon the glass plate 130. Thebearing assembly 132 includes an outer housing 134 and an inner bearing136. When the door 130 is closed, the horizontal central axis 133 of thedrum 100 is essentially coincident with an axis of rotation of the innerbearing 136 with respect to the outer housing 134. The inner bearing 136defines a receiving hole 138. The door 122 also includes a door housing140 that supports the glass plate 130. The door housing is coupled tohinge 124. Hinge 124 is a compound hinge that causes door motion to benearly parallel to the X axis as the door 122 moves to a closedposition. This allows the anterior end portion 116 of shaft 114 to bereceived into the receiving hole 138 as the door 122 closes.

FIG. 10 is a sectional view taken from AA′ of FIG. 9 to illustrateassembled components of the door 122. The bearing assembly 132 isaffixed to the glass plate 130. The outer housing 134 of the bearingassembly 132 is sealingly coupled to a central opening 142 in glassplate 130.

FIG. 11 is a detailed view taken from FIG. 10 to illustrate the centralpart of the door 122 in more detail. According to the illustrativeembodiment, the glass plate 130 has a central and circular hole 142. Theouter housing 134 of bearing assembly 132 is sealingly mounted to thecircular hole 142 in the glass plate 130. The inner bearing 136 ismounted inside a cylindrical recess 144 within the outer housing 134. Acircular ball bearing race 146 allows the inner bearing 136 to rotatefreely about a door central axis 148. The central hole 138 formed intothe inner bearing 136 defines a conical taper. The hole 138 tapersinwardly from its entrance 150 toward its bottom 152. When the door 122is closed, the taper is in the +X or frontward direction. In theillustrated embodiment, the door central axis 148 is substantially acentral axis for the opening 142, the central hole 138, and the axis ofrotation of the inner bearing 136 with respect to the outer housing 134.When the door 122 is closed, the door central axis 148 substantiallyaligns with the horizontal central axis of the drum 100. Such axes aresubstantially aligned in that they may be equal or not exactly equal dueto mechanical tolerances.

FIG. 12 is an isometric view of the agitator 110 in isolation. The shaft114 is elongate between the posterior end 118 and the anterior endportion 116. The anterior end portion 116 of shaft 114 defines a conicaltaper. The anterior end portion 116 tapers in a forward direction (i.e.,tapers towards the end of the anterior end portion 116). The shaftdefines a shaft axis 154. When the door 122 is open, some of the blades112 (of those closer to the anterior portion 116) rest upon the insidebottom surface 101 of the drum 100. Thus when the door 122 is open, theshaft axis 154 slopes downwardly relative to the horizontal central axis133 of the drum 100. As the door 122 is closed, the tapered hole 138engages (e.g., removably, slidably, receivably contacts) the anteriorend portion 116 of the shaft. The engagement lifts up the anterior endportion 116 and substantially aligns the shaft axis 154 with thehorizontal central axis 133 of the drum 100 and the door central axis148.

FIG. 13 is similar to FIG. 11 except that FIG. 13 includes the anteriorend portion 116 of shaft 114 received into the central hole 138 of innerbearing 136. This is a close up cross sectional illustration when thedoor 122 is closed upon the vertical opening 108. According to theillustrative embodiment, the central hole 138 of inner bearing 136 andthe anterior end portion 116 of shaft 114 both taper in the same forwardor anterior direction. This mutual taper facilitates the properreceiving and alignment of the anterior end portion 116 to the hole 138as the door 122 is closed. This mutual taper is mutual in the sense thatthe taper angle of the central hole 138 of inner bearing 136substantially matches the taper angle of the anterior end portion 116 ofshaft 114. Such taper angles substantially match in that they may beequal or not exactly equal due to mechanical tolerances. Similarly, suchtaper angles can substantially match in that notwithstanding differencesin the taper angles, the proper receiving and alignment of the anteriorend portion 116 to the hole 138 as the door 122 is closed is stillaccomplished. Just before the door 122 is closed, the narrowest end 156of the anterior end portion 116 is received within the wider entrance150 of the hole 138. Engagement of the conical surface of the anteriorend portion 116 with the conical surface of the hole 138 during finalclosure of door 122 self-aligns the axis 154 to the axis 148 and henceto the central axis 133 of the drum 100. This also lifts the blades 112off of the inside bottom surface of drum 100 and effectively centers theagitator 110 within the drum 100.

FIG. 14 is a method of self-aligning an axis of an agitator to an axisof a roasting drum in response to a door closure, according to anembodiment. FIG. 14 is described with respect to the embodimentdiscussed with respect to FIGS. 7-13 and 15-16, but it should beunderstood that the method of FIG. 14 can be performed with roastingsystems having differences from the embodiment discussed with respect toFIGS. 7-13 and 15-16. As discussed with respect to FIG. 14, method 160can “automatically” align an agitator 110 within a roasting drum 100 inresponse to the closure of the door 122. At 162, the door 122 is open(e.g., an open position) and the some of the agitator blades 116 restupon the bottom surface 101 of the drum 100. At 164, the door 122 ismoved toward closure (e.g., a closed position). At 166, inner bearing136 receiving hole 138 removably engages the anterior end portion 116 ofagitator 110 in response to the door 122 being moved toward closure. Aspart of 166, the narrowest end 156 of the shaft 114 is received in thewider entrance 150 of hole 138. At 168, the conical surfaces of theanterior end portion 116 and the receiving hole 138 engage andsubstantially self-align the axes 148 and 154 as the door 122 is movedto full closure. As part of 168, blades 116 are lifted off the bottomsurface 101 so that they can properly rotate within drum 100 without anyinterference with the inside surface 158 (e.g., without contacting theinside surface 158).

FIG. 15A is an isometric drawing of an embodiment of the roastingchamber assembly 4 with the door 122 removed. The drum has a concavecylindrical inside surface 158. The hatch 120 defines a portion of thelower or bottom surface 101 of the inside surface 158 of the drum 100.FIG. 15A depicts an “upper position” of hatch 120 whereby it seals anopening 170 formed into the lower surface 101. In the illustrativeembodiment, the hatch 120 closely matches the inside surface 158 of thedrum 100 so that there are no or minimal gaps or seams between hatch 120and inside surface 158.

FIG. 15B is similar to FIG. 15A except that the hatch 120 is in alowered state whereby the opening 170 is unsealed and open whereby beanswithin the drum 100 can begin to exit the drum 100 in a verticallydownward (−Z) direction into a cooling chamber (not shown). The opening170 has a long axis that is substantially parallel to the central axis133 of the drum 100. The opening 170 nearly spans the drum 100 along adimension parallel to the central axis 133 so as to allow a morecomplete emptying of the beans from the drum 100.

FIGS. 16A and 16B are isometric bottom view drawings of a lower outerportion of drum 100. FIGS. 16A and 16B illustrate the upper and lowerpositions of the hatch 120 respectively. In the illustrated embodiment,the hatch 120 is coupled a lower outside surface of the drum 100 by ahinge 172. The hinge 172 has an axis of rotation that is parallel to thecentral axis 133 of the drum 100. Also shown is the actuator 43 (alsoreferred to as a bean drop actuator 43 with respect to FIG. 2) that isconfigured to rotate the hatch 120 about the hinge 172 under control ofcontroller 42. In one implementation, the actuator 43 includes amotorized screw that extends and contracts the actuator 43 to providethe rotation of the hatch 120.

The opening 170 in the lower surface 101 of the drum 100 is bounded by avertical inward facing edge 174. The hatch 120 has an outward facingedge 176. When the hatch is in the upper (FIG. 16A) position the edges174 and 176 are in facing relation. The edges 174 are 176 are closelymatching so that there is a minimal gap there between.

When beans in drum 100 are finished with a roasting process, they aretransferred to a cooling chamber. FIG. 17 depicts a method 180 for thetransfer under control of controller 42. Method 180 corresponds to thebean drop step 66 of method 50 of FIG. 3. According to an initialcondition 182, the hatch 120 is in an upper (sealed) position asdepicted in FIGS. 15A and 16A. At 184, the actuator 43 is operated torotate and lower the hatch 120 to the lowered (open state for opening170) state as depicted in FIGS. 15B and 16B.

At 186, the agitator motor 41 is operated to rotate the agitator 110backwards and forwards about axis 154. This pushes the beans backwardsand forwards in a direction having a component parallel to axis 133 inthe drum 100 until they have essentially all fallen through the opening170 and into a cooling chamber. At 188, the actuator 43 is operated torotate and raise the hatch 120 to the initial upper (sealed) position.

The specific embodiments and applications thereof described above arefor illustrative purposes only and do not preclude modifications andvariations encompassed by the scope of the following claims.

What is claimed:
 1. A bean roasting system having a roasting chamberassembly, comprising: a roasting drum having an opening and having aninside surface with a back end and a front end, the inside surfacedefining a central axis of the roasting drum, the central axis of theroasting drum being substantially parallel to a support surface when thebean roasting system is disposed on the support surface; an agitatorhaving a plurality of blades mounted to an axial shaft, the axial shafthaving an anterior end portion and a posterior end portion, the axialshaft defining a central axis of the agitator that is substantiallyaligned with the central axis of the roasting drum; a motor thatsupports and is configured to rotate the posterior end of the axialshaft; and a door mounted rotationally relative to the opening of theroasting drum, the door including a glass plate to provide visual accessto contents inside the roasting drum when the door is closed over theopening.
 2. The bean roasting system of claim 1, further comprising: afront plate fixedly coupled to the roasting drum and defining an openingsubstantially aligned with the opening of the roasting drum, the doorrotationally mounted to the front plate.
 3. The bean roasting system ofclaim 1, wherein the plurality of blades are mounted to the axial shaftof the agitator at a plurality of locations of the axial shaft betweenthe anterior end and the posterior end of the axial shaft.
 4. The beanroasting system of claim 1, wherein: the plurality of blades include afirst subset of blades and a second subset of blades, the agitatorincludes a plurality of mounts that includes a first mount, a secondmount and a third mount, the first subset of blades mounted to the axialshaft of the agitator by the first mount and the second mount, thesecond subset of blades mounted to the axial shaft of the agitator bythe second mount and the third mount.
 5. The bean roasting system ofclaim 4, wherein each blade from the plurality of blades has its owncenterline that is not parallel to the central axis of the axial shaftof the agitator.
 6. The bean roasting system of claim 1, wherein theagitator has a plurality of corkscrew fins disposed about the axialshaft of the agitator.
 7. The bean roasting system of claim 1, wherein:the plurality of blades include a first subset of blades and a secondsubset of blades, the agitator includes a plurality of mounts thatincludes a first mount, a second mount and a third mount, the firstsubset of blades mounted to the axial shaft of the agitator by the firstmount and the second mount, the second subset of blades mounted to theaxial shaft of the agitator by the second mount and the third mount, theagitator has a first corkscrew fin and a second corkscrew fin, the firstcorkscrew fin disposed about the axial shaft of the agitator and betweenthe first mount and the second mount, the second corkscrew fin disposedabout the axial shaft of the agitator and between the second mount andthe third mount.
 8. The bean roasting system of claim 1, wherein: theplurality of blades include a first subset of blades and a second subsetof blades, the agitator includes a plurality of mounts that includes afirst mount, a second mount and a third mount, the first subset ofblades mounted to the axial shaft of the agitator by the first mount andthe second mount, the second subset of blades mounted to the axial shaftof the agitator by the second mount and the third mount, the agitatorhas a first corkscrew fin and a second corkscrew fin, the firstcorkscrew fin disposed between the axial shaft of the agitator and thefirst subset of blades, the second corkscrew fin disposed between theaxial shaft of the agitator and the second subset of blades.
 9. The beamroasting system of claim 1, wherein the anterior end of the agitator iscantilevered when the door is in an open position relative to theopening of the roasting drum.
 10. The beam roasting system of claim 1,wherein the glass plate of the door has a central portion that iscovered and does not provide visual access to contents inside theroasting drum when the door is closed over the opening.
 11. A beanroasting system having a roasting chamber assembly, comprising: aroasting drum having an opening and having an inside surface with a backend and a front end, the inside surface defining a central axis of theroasting drum; an agitator having a plurality of blades mounted to anaxial shaft that defines a central axis of the agitator that issubstantially aligned with the central axis of the roasting drum, theplurality of blades include a first subset of blades and a second subsetof blades, the agitator includes a plurality of mounts that includes afirst mount, a second mount and a third mount, the first subset ofblades mounted to the axial shaft of the agitator by the first mount andthe second mount, the second subset of blades mounted to the axial shaftof the agitator by the second mount and the third mount; and a doormounted rotationally relative to the opening of the roasting drum, thedoor including a glass plate to provide visual access to contents insidethe roasting drum when the door is closed over the opening.
 12. The beanroasting system of claim 11, further comprising: a front plate fixedlycoupled to the roasting drum and defining an opening substantiallyaligned with the opening of the roasting drum, the door rotationallymounted to the front plate.
 13. The bean roasting system of claim 11,wherein the plurality of blades are mounted to the axial shaft of theagitator at a plurality of locations of the axial shaft between ananterior end and a posterior end of the axial shaft.
 14. The beanroasting system of claim 11, wherein each blade from the plurality ofblades has its own centerline that is not parallel to the central axisof the axial shaft of the agitator.
 15. The bean roasting system ofclaim 11, wherein the agitator has a plurality of corkscrew finsdisposed about the axial shaft of the agitator.
 16. The bean roastingsystem of claim 11, wherein: the agitator has a first corkscrew fin anda second corkscrew fin, the first corkscrew fin disposed about the axialshaft of the agitator and between the first mount and the second mount,the second corkscrew fin disposed about the axial shaft of the agitatorand between the second mount and the third mount.
 17. The bean roastingsystem of claim 11, wherein: the agitator has a first corkscrew fin anda second corkscrew fin, the first corkscrew fin disposed between theaxial shaft of the agitator and the first subset of blades, the secondcorkscrew fin disposed between the axial shaft of the agitator and thesecond subset of blades.
 18. The beam roasting system of claim 11,wherein an anterior end of the agitator is cantilevered when the door isin an open position relative to the opening of the roasting drum. 19.The beam roasting system of claim 11, wherein the glass plate of thedoor has a central portion that is covered and does not provide visualaccess to contents inside the roasting drum when the door is closed overthe opening.
 20. The beam roasting system of claim 11, wherein theinside surface defines a central axis of the roasting drum, the centralaxis of the roasting drum being substantially parallel to a supportsurface when the bean roasting system is disposed on the supportsurface.